The room will be normal, with AC outlets. It's an office (with beautiful fluorescent available lighting). The "mobile" part just means that they need to be able to carry it into the office, setup, and breakdown without causing too much ruckus. I also get the feeling from them that this interviewee in particular is rather important and impatient at the same time, so a quicker setup is better.

LEDs were the first thing that came to my mind as well, but I've heard mixed reviews on their strength.